civiing now to syria, and the aivil war could be approaching a tonning point tonight. rebels are threatening the damascus airport. the assad regime's lifeline tots few remaining allies. charlie d'agata has more on this. >> reporter: the outskirts of amascus have become a grttleground with some of the fiercest fighting the city has seen yet. syrian rebels say they're closing in on the capital street by street. ow within their sights is their biggest target-- the damascus international airport, about 12 heles southeast of the city. poavy bombardment reported today in the suburbs in the surrounding area. rebel leaders called the airport a legitimate target, and gave a atark warning to the regime and outside travelers to avoid it at all costs. fighting near the airport force the suspension of commercial flights this week. some airlines have already stopped all together. a rebel takeover of the airport ould also cut off weapon supplies and regime allies like iran says andrew tabler of the washington institute of near wa east policy. >> as the country's longest runways, from